Hitherto, as the disc-shaped recording medium, a reproduction (playback) only read only memory (ROM) disc such as digital audio disc, etc. including reproduction (playback) only area where data are recorded by emboss pits, random access memory (RAM) disc including data recordable area by the magnetic recording film or the magneto-optical recording film, hybrid (type) disc including reproduction (playback) only ROM area where data are recorded by emboss pits and data re-recordable RAM area by the magneto-optical (MO) recording film, and the like are known.
In the hybrid disc, management information for carrying out management of data recorded in the reproduction (playback) only area is recorded in the reproduction only area, thus to carry out management of data of the reproduction only area on the basis of the management information reproduced from the reproduction only area. Moreover, management information for carrying out management of data recorded in the recordable area is recorded in the recordable area, thus to carry out management of the recordable area on the basis of the management information reproduced from the recordable area.
For example, in the optical disc, there is a hybrid optical disc in which the reproduction (playback) only areas and the recordable/reproducible areas are formed with the information recording surface being divided into such areas. In the optical disc device to which such hybrid optical disc is applied, desired data can be reproduced by the reproduction systems corresponding to respective areas, and desired data can be recorded by recording/reproduction systems corresponding to the recordable areas.
Namely, this hybrid optical disc is such that the area of the inner circumferential side is allocated (assigned) to the reproduction only area and predetermined data are recorded in advance in this area by emboss pits similar to those of the digital audio disc. On the contrary, the area of the outer circumferential side is allocated (assigned) to the recordable/reproducible area, and the magnetic recording film to be magnetized in a perpendicular direction of the disc is formed therein.
Further, as the optical disc system for scanning tracks formed in concentrical form or in spiral form by laser beams to carry out recording/reproduction of various data, there are known the optical disc system based on the CLV (Constant Linear Velocity) system for rotationally driving the optical disc at CLV to carry out recording/reproduction of data, and the optical disc system based on the CAV (Constant Angular Velocity) system for rotationally driving the optical disc at CAV to carry out recording/reproduction of data. Furthermore, in the case of the disc of the CAV system, there are instances where there is employed the zone CAV system in which because the recording density of the outer circumferential side is lowered, the transfer speed of the outer circumferential side is caused to be higher than the transfer speed of the inner circumferential side to allow the linear density of the inner circumferential side and that of the outer circumferential side to be the same.
In addition, the optical disc system based on the continuous servo system in which pregrooves continuously provided along tracks are used to carry out the tracking control, etc., and the optical disc system based on the sample servo system for carrying out the tracking control, etc. by making use of servo areas discretely provided on tracks are known.
Generally, the disc management area of the disc consists of a boot area, a data area management area, a root directory area, and a data area.
The boot area is the area for reading OS (Operating System) included (stored) in the data area to carry out starting of the system, and boot data, which are different for every kind of host computer are included (stored) therein. Moreover, the data area management area is the area for carrying out management of used (already used) area and unused (not yet used) area of the data area, and management data is rewritten every time rewrite operation of data is carried out. Further, the root directory area is the area for containing (storing) file information contained (stored) in the root directory, and data can be rewritten if the file name included (stored) in the root directory is rewritten, or is increased. In addition, the data area is the area in which the content of file and/or subdirectory information are included (stored).
Meanwhile, in the case of the hybrid disc including the ROM area and the RAM area, when the ROM area is disposed (allocated) at the leading side of the physical block address on the disc, the O-th address of the logical block address when viewed from the host computer side would be the leading portion of the ROM area, resulting in the problem that the hybrid disc cannot be used as the so-called boot device. Namely, since data, which are different for every kind of host computer are contained (stored) in the boot area for reading OS included (stored) in the data area to carry out starting of the system, the leading portion of the physical block address is required to be the RAM area.
Further, in the case of the hybrid disc employing the zone CAV system, when, e.g., the ROM area is disposed (allocated) at the inner circumferential side of the disc, it is inconvenient to contain (store), within the ROM area, picture data, etc. for which high speed transfer is required.
In addition, in the case where there is any defect in the RAM area, it is necessary to record in advance defect information indicating defect position in the Defect Management Area (DMA) to carry out recording/reproduction of recording data while avoiding the defect position. In the conventional hybrid disc, since the same defect information is recorded in respective defect management areas respectively provided immediately before and immediately after the user area collectively including the ROM area and the RAM area as shown in FIG. 1, the defect management area of the inner circumferential side and the defect management area of the outer circumferential side are greatly spaced (apart) from each other. For this reason, the seek operation in writing defect information requires much time, resulting in the problem that the access speed is lowered.
With the above in view, an object of this invention is to provide a drive apparatus and a drive method for a disc-shaped recording medium which can use the disc-shaped recording medium as the boot device, and a disc-shaped recording medium adapted thereto.
Another object of this invention is to provide a drive apparatus and a drive method for a disc-shaped recording medium, and a disc-shaped recording medium in which the seek time in writing defect information is shortened so that the access speed is permitted to be high.